Nokea
Regarding carbohydrate metabolism:
- A. glucokinase is increased in starvation
- B. the breakdown of glycogen is called glycolysis
- C. the direct oxidative pathway involves the breakdown of glucose through triose
- D. the conversion of pyruvate to acetyl-CoA is irreversible
Correct Answer: D
Rationale: Correct Answer: D - The conversion of pyruvate to acetyl-CoA is irreversible because it is catalyzed by the enzyme pyruvate dehydrogenase. This step is a key regulatory point in carbohydrate metabolism as it commits pyruvate to enter the citric acid cycle for further energy production. Reversing this step would disrupt the normal flow of metabolic pathways.
Summary of other choices:
A: Glucokinase is not increased in starvation; it regulates glucose uptake in the liver.
B: The breakdown of glycogen is called glycogenolysis, not glycolysis which is the breakdown of glucose.
C: The direct oxidative pathway involves the breakdown of glucose through glycolysis, not triose.
You may also like to solve these questions
Each of the following types of receptors is correctly matched with the response resulting from its stimulation EXCEPT:
- A. Muscarinic receptors - decreased heart rate
- B. Nicotinic receptors - decreased gastric acid secretion
- C. Alpha adrenergic receptors - increased blood pressure
- D. Beta adrenergic receptors - bronchodilation
Correct Answer: B
Rationale: The correct answer is B. Nicotinic receptors are not associated with decreased gastric acid secretion, but rather with muscle contraction at neuromuscular junctions. A: Muscarinic receptors stimulation leads to decreased heart rate via parasympathetic activation. C: Activation of alpha adrenergic receptors causes vasoconstriction and increased blood pressure. D: Stimulation of beta adrenergic receptors results in bronchodilation and increased heart rate. Therefore, choice B is the exception as it does not match the typical response of nicotinic receptors.
Which hormones of the adrenal glands supplement the sex hormones from the gonads?
- A. Mineralocorticoids, such as aldosterone
- B. Glucocorticoids, such as cortisol
- C. Gnadocorticoids, such as the androgens
- D. Epinephrine and norepinephrine.
Correct Answer: C
Rationale: The correct answer is C, Gnadocorticoids, such as the androgens. The adrenal glands produce androgens like DHEA which can supplement sex hormones from the gonads. Choice A, mineralocorticoids, control electrolyte and water balance. Choice B, glucocorticoids, regulate metabolism and immune response. Choice D, epinephrine and norepinephrine, are involved in the fight or flight response. Gnadcorticoids, specifically androgens, are the hormones from the adrenal glands that can supplement sex hormones from the gonads, making choice C the correct answer.
The left supra-renal vein drains into:
- A. Inferior vena cava
- B. Inferior mesenteric vein
- C. Left renal vein
- D. Superior mesenteric vein
Correct Answer: C
Rationale: The left supra-renal vein drains into the left renal vein. This is because the left adrenal gland is located above the left kidney, and the left renal vein is responsible for draining blood from the left kidney and adjacent structures, including the left adrenal gland. Therefore, the correct answer is C.
Incorrect options:
A: The inferior vena cava receives blood from various veins in the body but not specifically from the left supra-renal vein.
B: The inferior mesenteric vein drains the large intestine and does not receive blood from the left supra-renal vein.
D: The superior mesenteric vein drains blood from the small intestine and does not receive blood from the left supra-renal vein.
In summary, the left supra-renal vein drains into the left renal vein due to their anatomical proximity, making option C the correct answer.
The structure leading to the stomach is called?
- A. Pharynx
- B. Epiglottis
- C. Oesophagus
- D. Larynx
Correct Answer: C
Rationale: The correct answer is C: Oesophagus. The oesophagus is the structure leading to the stomach that carries food from the mouth to the stomach through peristalsis. The pharynx (A) is the throat cavity, the epiglottis (B) is a flap that prevents food from entering the trachea during swallowing, and the larynx (D) is the voice box. Therefore, the oesophagus is the correct answer as it specifically functions to transport food to the stomach.
From a medical perspective, ______ hormones can be taken orally because they are water-insoluble lipids and poorly digested.
- A. carbohydrate
- B. peptide
- C. protein
- D. steroid
Correct Answer: D
Rationale: The correct answer is D: steroid. Steroid hormones are lipid-soluble and can pass through cell membranes easily. This property allows them to be taken orally since they are not digested in the stomach and can be absorbed in the intestines. Carbohydrates (A), peptides (B), and proteins (C) are water-soluble and cannot pass through cell membranes easily, making them unsuitable for oral administration.